Members of the European Parliament discuss the decision adopted on a strategic framework for the Energy Union during a plenary session at the European Parliament in Brussels on Wednesday, Feb. 25, 2015. (AP Photo/Geert Vanden Wijngaert)

A Ukrainian prisoner of war prepares to check the body of an Ukrainian serviceman, retrieved from the rubble of the airport building, lies inside the destroyed terminal outside Donetsk, Ukraine, Wednesday, Feb. 25, 2015. Ukrainian troops held captive in the separatist stronghold of Donetsk began digging through the rubble Wednesday to retrieve the bodies of fellow soldiers killed last month in a bitter battle for the city's airport. (AP Photo/Vadim Ghirda)

BRUSSELS — European Union President Donald Tusk warned on Wednesday that the EU will not hesitate to impose new punishment on the separatists and Russia if the latest Ukraine peace deal collapses.

Tusk told the EU legislature on Wednesday that "additional sanctions remain on the table. We should be ready for any development — good or bad."

Ukraine says it will not begin pulling back heavy weapons under the peace deal until the latest cease-fire firmly takes hold. Rebels said Tuesday they were beginning a pullback, but the claim could not be independently confirmed.

Tusk said that since the Feb. 15 deadline to start the cease-fire, there had been some 800 violations.

The EU has imposed visa bans and asset freezes on 151 individuals and 37 entities and hit Russia with economic measures.

In France, Foreign Minister Laurent Fabius warned that the ongoing attacks should not spread further, including to the key city of Mariupol.

"We told the Russians clearly that if there is an attack by separatists in the direction of Mariupol things will be completely disrupted, including in terms of sanctions," Fabius told French radio.

In the European Parliament, there were calls for tougher action toward Russian President Vladimir Putin as the Minsk peace agreement became more fragile.

"To pre-empt further breaches of the Minsk II agreement, we should act now and prepare a new set of sanctions, which we can directly put in place if this Russian aggression continues," said Guy Verhofstadt of the ALDE liberal group.

Tusk said it was essential to maintain unity in support of Ukraine.

"One of the most important goals for President Putin today is to divide Europe and the whole Western community," Tusk said.